Using the command line interface of debug

Aliases with arguments

The built-in aliases are all simple aliases that do not take any arguments, but you may define your own that take arguments. If your alias definition includes the special identifiers $1 or $2 for example, then when you use the alias, each instance of $n will be replaced with the nth argument in the invocation. For example, here is an alias to print a section of an array:

   debug> alias parray {set $i = $2; \
   >while ($i < $3) {print -f"[%d] = %z\n" (int)$i, $1[$i]; set ++$i}}
   debug> parray arr 2 4
   [2] = 100
   [3] = 53
   [4] = 11

You may also use the special identifiers $# and $* in an alias. When the alias is invoked, $# is replaced with the number of arguments actually given, and $* is replaced with a list of all the arguments, separated by spaces. For example, you can write an alias to set a breakpoint at the given address, or, if no arguments are given, set the breakpoint on the last line displayed:

   debug> alias b if ($# > 0) {stop $*} else {stop %list_file@%list_line}
   debug> b main
   EVENT [1] assigned
   debug> b
   EVENT [2] assigned